Answer:
y = -x - 4
Explanation:
the equation of a linear graph is y = mx + b
you know the m = -1
so now the equation is y = -x + b
from here, what you could do to find b is...
plug (-1, -3) into the equation
1) x = -1, y = -3
2) -3 = -(-1) + b
3) -3 = 1 + b
4) -4 = b
or you can look at the y-intercept which is where the line intersects with the y-axis
it seems to be (0, -4)
so "b" would be equal to -4
this makes the final equation y = -x + (-4) or y = -x - 4